Machine and method for making solid comminuted material



Y 193$ J. L. STECHER ET AL. 2,047,391

MACHINE AND METHOD FOR MAKING SOLID GOMMINUTED MATERIAL Filed Nov. 1'7, 1933 v 4 Sheets-Sheet l I Joseph Z..Sfecher Marion gflmz'ck INVENTORS Charles [Danie/s BY xxx; 5%

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4 Sheets-Sheet 2 INVENTORS A TTORNE Y.

Y 1936- J. L. STECHER ET AL MACHINE AND METHOD FOR MAKING SOLID COMMINUTED MATERIAL Filed NOV. 17, 1955 July 14, 1936.

J. L. STECHER ET AL MACHINE AND METHOD FOR MAKING SOLID COMMINUTED MATERIAL Filed NOV. 17, 1935 4 Sheets-Sheet 5 w w N T N M; NN wwkw m 3* mm mm 3 w% w Fm 4mm A W L $.00 1 J a w w w J fir f, %N Y, w w E W m M W N P v w %v\ mm m l W W V I m k m .QNY QN 9W m m QN @N WW y 1936' J. L. STECHER ET AL 2,047,391

MACHINE AND METHOD FOR MAKING SOLID COMMINUTED MATERIAL Filed Nov. 17, 1933 4 Sheets-Sheet 4 Warm/2 @flmzck Char/e5 506221'6/5 B Y Y {M 25% A TTORNE Y.

Patented July l4, 1936' MACHINE ANDME 'rnon FOR. Mame SOLID COMMINUTED MATERIAL Joseph L. Stecher, Wilmington,

Del., Marion G.

Amick, Boothwyn, Pa., and CharlesE. Daniels,

Wilmington, Del., assignors to E.

I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware Application November 17, 1933, Serial No. 698,384 6 Claims. (01. 29-45) This invention relates to a machine and method for making solid comminuted material directly from molten material and to the product obtained thereby.

-In the manufacture of alkyl lead compounds, an alkyl halide is reacted with a lead sodium alloy. In order for this reaction to take place in an efficient and economical manner, the leadsodium alloy must be finely divided and in such condition that it will react readily with the alkyl halide. In the preparation of such alloy,- it has generally been considered necessary to [melt the sodium and lead together and cast the material in the form of billets or .pigs. When the cast material has cooled and solidified, it has then become necessary to break them up into pieces of a size to be readily handled'and then ground or. crushed in-a crusher or other form of grinding mill. This method of making the flnely divided lead-sodium alloy-has proved to be very unsatis- .fact ory,'inefiicient, and wasteful. This type of alloy is subject to rapid deterioration in the Such derial as the deterioration products will not take part in the reaction to form the desired reaction products. Also, when it is attempted to grind this, material; the material tends to pack and jam,.requiring stopping of the grinding operations,.dismantling of the crusher or grinding mill and cleaning of the same. This results in a -was'te of much time and labor and the loss of valuable material due to oxidation and the action of moisture in the atmosphere necessarily ad,-'

mitted into contact with the alloy inJ'the millwhen-the mill is dismantled.

Other metals and their alloys have similar characteristics and properties which render it extremely di'm'cult and costly-to prepare them 1 in finely divided form.

An object of the present invention is to provide a novel device which is adapted for the prepara-' tion of solid comminuted material directly from molten material.

A further object is to provide such a device whereby such solid comminuted material maybe made in a more efl'icient," economical and rapid manner than has been possible With devices heretofore employed. A' still further object is to provide a novel method of manumaterial directly facturing solid comminuted from molten material. Anotherobject-is to'provide a new method whereby solid'comminuted material may ber'nanufactured in a more efficient, economical and rapid manner. Still another object is to produce comminuted materialin a novel form. Other objects are toadvance. the art. Still other objects 'will appear hereinafter.

These objects may be accomplished in accordance with our invention which comprises the 5 novel device disclosed in the drawings and described hereinafter, together with themethod of employing the same andthe products produced thereby. I Referenceis to be had to the accompanying drawings forminga part of this specification, in which similar reference characters refer to similar parts throughout the several views.

Figure 1 is an elevational view of our device with parts of the bed plate broken away for the 15 .sakeof clearness in illustration.

Figure 2 is a vertical longitudinal section of the apparatus shown in Figure 1.

Figure 3 is an enlarged elevational view in perspective of the rotary member with' the surrounding shell shown partly in section to illustrate the relation of parts.

Figure 4 is a perspective elevational view -of one of the edged tools detached from the rotary member.

Figure 5 is a perspective view of the stationary shell with parts broken away and the end flanges removed to more clearly. illustrate the arrangement of the partitions.

Figure 6 is a view in cross section of the shell, taken .on lines 6-6 of Figure 2'. 1

Briefly, our devicecomprises essentially a stationary jacketed shell having an inner smoothcylindrical surface and a rotary member positioned withinthe shell and having an outercylindrical surface positioned adjacent to but spaced from the inner surface of the shell. The rotaryare suflicient in 'numb'er and so positioned relatively to eachother that they form an interrupted spiral advancing from the charging end to the discharging end of the shell and sweeping the entire innercylindrical surface of the shell in a'single' rotation of'the rotary member.

These projections are adapted to throw molten 'material, deposited on the rotary member, onto the inner cooledicylindrical surface of the shell, where the molten material is cooled and solidifled, remove the solidified material from the in- W ner cylindrical surface of the shell, comminute such removed material, and move it to the discharge outlet of the shell. It appears to us that the material is cut and ground;

The stationary shell comprises an upper semicyllndrical half I and a lower semi-cylindrical half I2. Each of the projecting flange l4 extending along each of the longitudinal edges thereof provided with openings for bolts l6- or other suitable securing de vices for properly securing the two halves together. Each semi-cylindrical half, also, has an outwardly projecting annular flange l8 at each end thereof. The upper cylindrical half of the shell has a charging inlet 20 positioned" at the top and at one end thereof. The lower cylindrical half has a large discharge outlet 22, substantially rectangular in horizontal cross section, positioned at the bottom thereof. This discharge outlet is at the opposite end of the shell from the charging inlet.

Each semi-cylindrical half also has an outer substantially. semi-cylindrical shell or jacket 24 covering the outer surface thereof but spaced therefrom so as to provide a semi-annular space 26. This space 26 is provided for the circulation of a fluid heat transfer medium for maintaining the shell and the inner cylindrical surfaces thereof ata predetermined temperature, The jacket onthe upper half of the ;shell has two inlets 26 positioned at opposite sides of the jacket adjacent to the longitudinal flanges thereof at one end. An outlet 36 is provided at the top ofthe jacket near the opposite end thereof. The

jacket, on the lower half of the cylindrical shell,-

has. a fluid inlet 32 positioned at the bottom and adjacent one end thereof. Two fluid discharge outlets 34 are provided at opposite sides of the jacket of the lower cylindrical half and adjacent longitudinal flanges l4 at the other end thereof.

Short partitions v36 are positioned in the spaces 26 between the jackets 24 and the semicylindrical shell halves I0 and I2. These partitions 36 are provided in longitudinally spaced pairs, the members of each pair extending circumferentially from the longitudinal flanges l4 toward each other. However. these partitions terminate short of the median of the semi-cylindrical halvesand of each other so that there is an opening between their. opposed ends for the passage of fluid around the same. Longer partitions 36, positioned in the space 26, extend circumferentlally across the. medians of the semi-cylindrlcal halves and have their ends terminating short of the longitudinal flanges l4 and intermediate of the lengths of partitions 36. These partitions 36 are positioned intermediate the pairs of partitions 36 longitudinally of the semi-cylindrical halves. Additional short partitions 40 are provided in the space 26 of the lower cylindrical half of the shell adjacent the inlet 32. These short partitions 46 are spaced from the flanges l4 and the median of the cylindrical half. These additional partitions 46 preventthe accumulation of steam or other vapors of the heat transfer medium adjacent the flanges l4 at the inlet end of the jacket.

The lower half of the shell is provided with brackets or feet 42 for supporting the shell on a suitable bed plate 44. Thesefeet 42 are four in number, there being two on each side of the shell.

These feet may -be secured to the bed plate bybolts or other suitable securing means.

The ends of the shell are hermetically closed by circular headers 46 which are secured to the halves has an outwardlyannular flanges l8 by means of bolts or other suitable securing means. The headers are provided with circular openings at the center thereof for the rotating member 50. Suitable packing boxes are provided for preventing gases or liquids from entering onleaving the shell through the openings duringoperation.

, The rotary member comprises a shaft 48 and a drum supported by and rigidly secured thereto. The drum comprises a. cylinder 50 closed at the ends by circular'walls 52. Thecircular walls 52 have outwardly projecting cylindrical members 53 which are adapted to project and rotate in the circular openings and packing boxes in the headers 46. The drum 5!! is provided with an inner cylindrical shell or jacket 54 adjacent to but spaced from the cylinder 50 to provide an annular space 56 for the circulation of a heat transfer medium. A partition 58 is positioned in the space 56 and surrounds the jacket 54. This partition 58 is in the form of a spiral advancing from one end to the other of the annular space 56.

One end of the shaft 48 is bored to form a fluid inlet 60 which extends into the drum and connects with inlet 62 opening into the space 56 through the Jacket adjacent one end thereof. The other end of the shaft 48 is provided with a fluid outlet 64 which extends into the drum and connects with a fluid outlet 66 opening into the space 56 at the opposite end of the jacket to the inlet 62 and at the opposite side of the jacket 54. The ends of the shaft 48 are provided with suitable stufling boxes 66 and nipples 10 for connection to a supply of the fluid heat transfer medium to be circulated through the annular space 56.

The cylinder 50 has an outer cylindrical surface concentric with the inner cylindrical surface of the shell. Also, the cylinder 50 is of such diameter that the outer cylindrical surface thereof is positioned adjacent to the inner cylindrical surface of the shell but spaced therefrom. The cylinder 56, in the outer surface thereof, is provided with openings or sockets for elements 12. These elements are rigidly secured to the cylinder 50 and project outwardly from the cylindrical surface thereof in a radial direction. The edges of the elements are positioned closely adjacent to the inner cylindrical surface of the shell so as to remove and scrape therefrom, material which may be deposited on such inner cylindrical surface. These elements are arranged in horizontal rows extending longitudinally of the drum, each row containing a plurality of such elements. The

- drical surface. 'These elements are made of tool steel and are ground and shaped in the manner of a metal flnishing tool having a front clear- 35 ance of about 5 anda top rake of about 5. These proportions of the elements may be varied a few degrees one way or another to suit the class of material being treated, as is thecase of all metal cutting tools. Each element will also have 70 .lts operating edge set atabout 45 to the line of forward travel or rotation of the drum. However, this angle may also be varied in accordance with the material being treated. If desired, these elements may be adjustably secured within Miv their sockets so that the angle' of the edges relative to the forwardline of travel of the elements may be adjusted for the treating of different materials.

The shaft 48 is supported in heavy bearings 14 so that the drum and the elements will run concentrically with the inner cylindrical surface of the shell. These bearings may be supported on the base plate supporting the stationary shell, if desired. The shaft 48 also carries a pulley'1o which is to be connected to a. motor or other suitable driving means for rotating the shaft. Also,

other means may be employed for rotating the shaft, if desired.

By the use of the hereinbefore described device,

we are enabled to produce solid-comminuted material-directly from molten material more efiiciently, economically and rapidly than has heretofore been possible. In the operation of this device in accordance with our novel method, the material to be comminuted is charged through the inlet 20 in the molten state. This molten material falls upon the surface of the drum 50 which is rotating at a speed of about 150 to 350 R. P M. The molten material .is thrown off from the drum by-centrifugal'force and against the inner cylindrical surface of the shell. The elements 12 act as paddles, during such rotation, to aid in throwing the molten material against the surface of the'shell. The molten material is partly cooled upon coming into contact with the cooled surfaces of the rotary member or drum 50 and further cooled to below itssolidifying point upon the inner cylindrical surface of the shell. Themolten material thus solidifies upon the inner surface of the shell and the elements thereupon remove the solidified material from the surface of the shell. These elements also act to comminute the material which has been removed. Furthermore, due to the elements being so positioned as to form a broken-spiral or helix, the removed and comminuted material is fed .by means of the elements toward the discharge outlet where the comminuted material discharges into a suitable container which is preferably in the form of a weighing tank. The rate of feed of the molten material into the device will be varied with the speed of rotation of the rotary vmember. The size of the comminuted particles produced may also be varied by varying the rate of feed of material for any given speed of the rotary member. For example, if it is desired to make very finely comminuted material, the rate of feed should be slow and the speed of the rotary member should be high. If it is desired to have the comminuted material in larger particles, a greater rate of feed of material should be employed or the speed of the rotary member should be decreased. However, the speed of the rotary member should always be sufficient so that the molten material will be thrown out and away therefrom by centrifugal force. Such speed of the rotary member will, of course, vary with the character of the'material being treated.

In order to more clearly illustrate the method of operating my device the following example is given:

Example A lead-sodium alloy, comprising 90% lead and 10% sodium in molten state and'having a temperature of from 370-to 420 C., was charged intothe device at rates of feed varying from 1 to 500 pounds per minute. The rotary member was driven at a speed of from 150 to 350 R. P', M,

pounds per minute and the speed of the rotary member was 250. R. P. M., the comminuted material'had a particle size of about 60 mesh. When the rate of feed was 200 pounds per minute and the speed of the rotary member was 150 R. P. M.

the particle'size of the comminuted material was about 40 mesh.

We have further found that the material, produced in accordance with our method employving our-novel device, has certain characteristics and properties which comminuted materials, obtainedby other methods, do not have. The material, produced in accordance with our method,

will usually be found to be in the form of small a glomerates which are porous. Thesecharacteristics of the material, produced in accordance with our process, are of material advantage where the comminuted material is to be employed in a chemical reaction. Where the comminuted material either acts as a catalyst or'takes part in the reaction, we have found these characteristics of the material to be highly advantageous. When a lead sodium alloy, produced by this method, is employed in the manufacture of alkyl'lead compounds, the use ofsuch material results in a smoother, more efiicient and complete reaction at higher speed than is possible with similar material obtained by otherprocesses.

While we have disclosed'the preferred embo'diments of our invention, it will be readily apparent to those skilled in the art that many variations and modifications may be made therein without -molten material, instantaneously, upon cooling of said material, removing the solidified material from the cooled surface, and simultaneously comminuting the removed material, so that such cooling, removing and comminuting areperformed without appreciable lapse of time between them.

' 2. Lead-sodium alloy obtainable by the method of claim 1. i v 3. In a machine adapted to the solidifying and comminuting of molten metal in the character of molten lead-sodium alloy, without appreciable lapseof time between solidifying and comminuting, in combination: a stationary, horizontal, cy-

lindrical drum-like shell, having provisions for cooling thesame and also having a smooth uninterrupted inner periphery, whereby the shell is adapted to receive upon its inner surface the molten metal to be comminuted, as thrown thereon by the hereinafter recited rotor, and to cool and solidify the same in condition to be readily removed from such surface, a rotor concentrically received in said shell and of a diameter closely approaching that of the interior of the shell, said rotor being providedsubstantiallythroughout its 1 length, with a plurality. of radially projecting spirally arranged edged tools of a length to approximately bridge the space between the rotor and the shell, thus to bring the ends of the tools into close proximity to the shell, said shell being provided with a charging inlet and a discharge outlet, both of small area relative to the surface of the shell, wherefor the shell fully surrounds the rotor, said inlet and outlet being spaced apart along the length of the rotor and ,said inlet being located upon said shell in posecuring the same together, each semi-cylindrical half having a jacket covering but spaced from the outer surface thereof and rigidly secured thereto, a plurality of partitions in the space between the jacket and the outer surface of each semi-cylindrical half, short longitudinally spaced pairs of said partitions extending circumferentially from opposite longitudinal edges of each semi-cylindrical half and terminating short of the median of the circumference thereof alternated with single long partitions extending cir- I cumferentially across the median of the circumference of the semi-cylindrical half and terminating short of the longitudinal edges thereof and intermediate of the lengths of the short partitions, each of said jackets having inlets and outlets at opposite ends thereof whereby a fluid heat transfer medium may be circulated through the spaces between the jackets and the semicylindrical halves.

6. 'In a device for making solidcomminuted material. a stationary jacketed shell having an inner cylindrical surface, a rotary member within the shell, said rotary member comprising a rotary shaft, a cylinder rigidly mounted on said shaft and having an outer cylindrical surface positioned adjacent to but spaced from the inner cylindrical surface of the shell, an inner cylindrical jacket positioned adjacent to but spaced from the inner surface of the cylinder, a spiral partition between the jacket and the cylinder extending circumferentially of the jacket and advancing from one end of the jacket to the other end, a fluid inlet extending through one end of the shaft and into one end of the space between the jacket and the cylinder, a fluid outlet extending through the other end of the shaft and into the other end of the jacket whereby a fluid heat transfer medium may be circulated'through the space betweenrthe jacket and the cylinder, edged tools rigidly secured to and projecting from the outer cylindrical surface of the cylinder and having their edges positioned closely adjacent to the inner cylindrical surface of the shell, and means for rotating the rotary member.

JOSEPH L. STE'CHER. MARION G. AMICK. CHARLES E. DANIELS. 

